1. Field of the Invention
The present invention relates to a method for looking up table for data transferring in the circuit, and more particularly, to a look-up table that is required during looking up table for data transferring and a method for looking up table thereof.
2. Description of the Related Art
For obtaining a higher precision, it is common that a very complicated and time consuming calculation is required for both the look-up table during looking up table for data transferring in the digital circuit and the method for looking up table thereof. In order to accomplish such complicated and time consuming calculation, it is required to use a hardware of very high cost or a grate amount of the system resources. In addition to the precision requirement, efficiency with reasonable cost is also required, thus it is inadequate in the physical circuit design. Therefore, the complicated and time consuming calculation may be replaced with the method for looking up table. In such case, if the variant range extended, a larger size of the look-up table is required. For the application which has memory limitation or has higher workload for accessing the memory, if the size of the look-up table used in the method for looking up table is too big, it causes more trouble. An example of this is the quantization and de-quantization processes in the digital signal coder/decoder (CODEC).
In the decoder configuration of “An Optimized Software Solution for an ARM Powered™ MP3 Decoder” proposed by ARM (Advanced RISC Machines) Inc., an improved method of de-quantization in the decoder of the digital music format MP3 is provided. However, it cannot eliminate the high error problem.